Hmm, guess I'll throw my hat into this ring.......Internet works if you know what yu're looking for specifically (i.e. Give me a 1080 foil in size 26.5)..........even if you know what size your shoe converts to in Mondo Point sizing (what ski boots size with)..every company has a different fit (generated through shell width, liner type, materials, etc, etc).........if you go to a shop and have people do a good boot fitting on you (meaning they actually check the liner, put in an aftermarket footbed for you to test, even go so far as to do canting, spoiler changes, etc) buy the boots from them or give them the option to match the prices you've seen......and Yes, I do run an online and real-life ski store.........and it blows smoke up my ass when you dial in the fit on somebodies boot for an 1 1/2 hours and then they tell you thanks but no thanks.
Not to be a jerk or anything.....I just know that when I do a bootfitting, you're gonna be hard to pressed to make that boot fit that good (even if you buy the same exact boot online)...............
Now, if you want to buy boots online....my shop and several others offer the option for you to purchase two pairs of boots and a return UPS label so if you're having a tough time deciding, you can get them both...try them and return whatever size doesn't work.